MSIS-3223 EXAM 2 (OKSTATE)
QUESTIONS AND ANSWERS
What are the three definitions of probability? - Correct Answers -Classical, relative
frequency, subjective
What is a random variable? - Correct Answers -Numerical description of experiment
outcome
What is the difference between a discrete and continuous random variable? - Correct
Answers -Discrete: countable outcomes, continuous: outcomes over intervals
What is the expected value of a random variable? - Correct Answers -Corresponds to
mean or average for a sample
How do you find joint probabilities? - Correct Answers -Multiply the probabilities of the
two events
How do you find conditional probabilities? - Correct Answers -Divide the joint probability
by the probability of the given event
How do you identify that two events are independent? - Correct Answers -If the
occurrence of one event does not affect the probability of the other event
What is the classical definition of probability? - Correct Answers -Probabilities deduced
from theoretical arguments
What is the relative frequency definition of probability? - Correct Answers -Probabilities
based on empirical data
What is the subjective definition of probability? - Correct Answers -Probabilities based
on judgment and experience
What is the range of probabilities? - Correct Answers -Between 0 and 1
What is the expected value helpful for? - Correct Answers -Making a variety of decisions
What is the expected value equivalent to? - Correct Answers -Mean or average for a
sample
, What is the probability of a respondent being female and preferring Science? - Correct
Answers -Unknown, not enough information given
How can you determine if two events are independent? - Correct Answers -If the
probability of one event is not affected by the occurrence of the other event
What is the purpose of using a cross-tabulation? - Correct Answers -To analyze the
relationship between two variables
What is the purpose of finding joint probabilities? - Correct Answers -To determine the
probability of two events occurring together
What is the purpose of finding conditional probabilities? - Correct Answers -To
determine the probability of one event given that another event has occurred
What is the weighted average of the squared deviations from the expected value? -
Correct Answers -Variance of a discrete random variable.
What does the variance measure? - Correct Answers -Uncertainty of the random
variable.
What is the normal distribution? - Correct Answers -Continuous distribution described
by a bell-shaped curve.
What are the parameters of the normal distribution? - Correct Answers -Mean and
standard deviation.
What are the properties of the normal distribution? - Correct Answers -Symmetric, zero
skewness, mean=median=mode, unbounded range.
What are the empirical rules for the normal distribution? - Correct Answers -68-95-99.7
rule.
What are probability density functions? - Correct Answers -Distributions that
characterize outcomes of continuous random variables.
What are the properties of probability density functions? - Correct Answers -Graph lies
at or above x-axis, total area under the function is 1, infinite number of values.
What does a probability density function calculate? - Correct Answers -Probability of a
random variable lying within a certain interval.
What is regression analysis? - Correct Answers -Statistical technique for modeling the
relationship between variables.
QUESTIONS AND ANSWERS
What are the three definitions of probability? - Correct Answers -Classical, relative
frequency, subjective
What is a random variable? - Correct Answers -Numerical description of experiment
outcome
What is the difference between a discrete and continuous random variable? - Correct
Answers -Discrete: countable outcomes, continuous: outcomes over intervals
What is the expected value of a random variable? - Correct Answers -Corresponds to
mean or average for a sample
How do you find joint probabilities? - Correct Answers -Multiply the probabilities of the
two events
How do you find conditional probabilities? - Correct Answers -Divide the joint probability
by the probability of the given event
How do you identify that two events are independent? - Correct Answers -If the
occurrence of one event does not affect the probability of the other event
What is the classical definition of probability? - Correct Answers -Probabilities deduced
from theoretical arguments
What is the relative frequency definition of probability? - Correct Answers -Probabilities
based on empirical data
What is the subjective definition of probability? - Correct Answers -Probabilities based
on judgment and experience
What is the range of probabilities? - Correct Answers -Between 0 and 1
What is the expected value helpful for? - Correct Answers -Making a variety of decisions
What is the expected value equivalent to? - Correct Answers -Mean or average for a
sample
, What is the probability of a respondent being female and preferring Science? - Correct
Answers -Unknown, not enough information given
How can you determine if two events are independent? - Correct Answers -If the
probability of one event is not affected by the occurrence of the other event
What is the purpose of using a cross-tabulation? - Correct Answers -To analyze the
relationship between two variables
What is the purpose of finding joint probabilities? - Correct Answers -To determine the
probability of two events occurring together
What is the purpose of finding conditional probabilities? - Correct Answers -To
determine the probability of one event given that another event has occurred
What is the weighted average of the squared deviations from the expected value? -
Correct Answers -Variance of a discrete random variable.
What does the variance measure? - Correct Answers -Uncertainty of the random
variable.
What is the normal distribution? - Correct Answers -Continuous distribution described
by a bell-shaped curve.
What are the parameters of the normal distribution? - Correct Answers -Mean and
standard deviation.
What are the properties of the normal distribution? - Correct Answers -Symmetric, zero
skewness, mean=median=mode, unbounded range.
What are the empirical rules for the normal distribution? - Correct Answers -68-95-99.7
rule.
What are probability density functions? - Correct Answers -Distributions that
characterize outcomes of continuous random variables.
What are the properties of probability density functions? - Correct Answers -Graph lies
at or above x-axis, total area under the function is 1, infinite number of values.
What does a probability density function calculate? - Correct Answers -Probability of a
random variable lying within a certain interval.
What is regression analysis? - Correct Answers -Statistical technique for modeling the
relationship between variables.
